Carburetor



Nov. 21, 1944. M, MALLORY 2,363,346

CARBUREIOR Filed Mrch 2, 1942 IN VEN TOR. MARION MALLORY Patented Nov. 21, 1944 name-o ,s'rni'as FF= I CE ommncron .MarionIMallory, Detroit, Mich. .n iieafiun ivrammz, 1942,?SefialiNo. 4mg

' iaoiaims. trowel-.41) I Th -ist'inventionarelates to a i-cai buretor.

It is old in oaibi-lr etors ts vary the .lratio of iiu-l to air according 130 the*requirementsof lthe engine. I-nus. when. the*iengirre operating richer mixture is supp1ied the-'engine than when the engine 'is' operating =-under partload' or at part upen throttle.

It is itheobject of this invention to produce .a marJou-retor that will enrichen ithe fue'l "mixture whenever the rengine-is operating under a con- -s'idera bleaor heavy load. 1

F-his invention also contemplates a carburetor wherein the fue-l -ismetered throughout the seritire range of'ifuel "mixture ratio. This 'ob'iec't "is ,iiul to the power jet is metered in accordance w-iih the opeiiing and-tilosing df thathrottlewalve.

The drawing islaverficabcrosssection through iire 'improvedioarburetor.

The car-b retor comprises a; housing provided with an eiir Inlet I "and 'a iuel mixture 'outlet *into manifold of the engine. The throttle waive is designated andwhe aiir valve 4. f Ihe throttle valve -B- and air waive -"4 are "connected -togletflier so thaft theyopen and -closein -'sy-neohronism. Thisis accomplished by means -=of "a lirik 5 connected at one end "to arm "5 an'd at thepth'er en 'd to arm 1. 6 is fixedon shaft shaft !)which supportsithrottle"valve 3.

ilhe mixing chaniber'is designated N1 and the zful *is delivered ime the mixingchamber through jet H. Jet II is connected with' 'the *ful bowl by passageway W2 and orifice [3. Jet II is also connected with the fuel bowl by orifice M, passageway I5, orifice l6 and passageway 11 which connects into passageway I2 between jet H and orifice I3. Orifice I6 is controlled by valve l 8 which is connected to piston i9 by bridge 20. Piston I9 is mounted in cylinder 2|. A compression spring 22 is mounted between the bottom of cylinder 2| and piston l9 so that spring 22 tends to raise piston i9. The lower end of cylinder 2| is connected by means of passageway 23 and orifice 24 into the carburetor passageway on the engine or fuel mixture outlet side of throttle valve 3.

The fuel flowing through orifices l3 and I4 is metered "by -metering pin *25 -connected bylin-k with a-rml. Me'teri-ng xp'in' 25 is provided on its opposi te sides with fiat tapersZJ which meter the fuel 'ifiowingf' through orifices lfi and M. Since metering pin -25 is connected by link "-28 with -'arm "as throt tle Vaiive 3 opens, metering pin 25 1s raised-"so -that fiat tapers 2! cooperate 'with ofi-fices W3 and --M to increase the amountm f ful thatiean' fiowthroug'h ithes'e orifices. inuriing th'e operation of the carburetor, fuel flows Leominuousiy through orifice i=3, passageway in and jet I ilout fu'el flows through -orifice W4 apas- -sageway iti orifice i115 and passageway 1 i into rpassageway w iorily wnen valve {18 has been moved to open position by' spring 22, as described below. 7

' lithe operation :of the carburetor is as follows: when tlre engine 'is rial-mg, throttle valve 3 and *:air axial-we '4 Lara-almost closed so' tha'it 'jus't stifiiacierrtzair mews "the carburetor to -mai'n etain the engine .fi-dliitg. :Ht -this time meter ing rpm ralmost :closes orifice 13 :so orily stiflilc-ient fuel "'iirawn 'r throughmrlifiee 4-3,- pa-ssage wayallzandxjetI-hl to ke'ep the engine idling. A t sifdie position of ethrottllewalve $3 the vacuum existring zthe engine side :of fthrottle valve :3 and in passageway 23 "and cylinder an draws piston Hi [flow-n1 compressing spring :22, zthis aiso rn eves valve wwlpwn" so tthat zit-shuts off orifice' l'fi. -W-hen valve ii8 misses-prince 46 mo fuel can 'ifiow orifi-ce 2M through zpassagewaiy 15 lintopassageway H1. cAs :the zthrottle'vaive reopenedair valve 4 "also "open "andithe meteri-ng pin slikewisewwillsise :so that fiat tapers 12.1 increase *lthewamount .iof'iopening at orifices as. and in. Jf,':h0W6Ver,ith -3 ilhll'flilflflWlVG 3 is not ope-n far enough to apply a aconsidera'ble lload ont'he engine. the vacuum -on 'the outlet :side :of throttle Naive at: orifice i2 4 will -:remain rhig h- "enough to acompress :spring 22 and hdid zpiston it!) and valve itmdownward ly to shutaoff' orifice i6. 'aAs iso'o'nza's the throttle is opened wide enough .to apply considerable, but not necessarily full load on the engine, the vacuum below the throttle valve 3 at orifice 24 will collapse thereby permitting spring 22 to raise piston l9 and valve I8 which opens orifice 16. As soon as orifice I6 is open, fuel flows through orifice I4, passageway l5, orifice I 6, passageway I'I, into passageway l2 where it joins the fuel passing through orifice I3 into passageway l2, and then flows through jet ll into the mixing chamber Hi. This additional fuel flowing through orifice l4, passageway l5, orifice l6. and passageway I1 into passageway l2 increases the richness of the fuel mixture flowing into the engine whenever the engine is operating under a considerable load.

The greater the vacuum in the intake manifold the better the fuel is atomized or mixed with the air and the more thorough becomes the combustion in the cylinder. Therefore, at high manifold vacuum a leaner or more economical fuel mixture can be used. If good acceleration of the engine is desired under low manifold vacuum conditions, then a higher fuel mixture ratio must be used because a poorer atomization of the fuel will be obtained and more fuel must be supplied to get the power desired. Thus, the tension .of spring 22 will be such that it will open valve [8 whenever the vacuum in the intake manifold or. on the engine side of valve 3 falls below a pre-. determined vacuum which will largely be determined by the performance desired from the 'engine associated with the carburetor. Preferably,

the power jet cuts in only when the engine is subjected to aconsiderable load, such as occurs when the throttle is moved to wide or nearly wide open position, and such as occurs at low engine speeds when the throttle is moved only part way open from idle or close to idle.

As herein shown, jet H serves a dual purpose, namely, it supplies the engine with the fuel metered through orifice i3 and it also serves as a power jet to supply the engine with the fuel metered through orifice l4 when valve 18 is open. Obviously, by using jet II for this dual purpose, a more simple construction of carburetor is obtained. However, if desired a separate jet can be provided for supplying the engine with the fuel metered through orifice I 4.

I claim:

1. A carburetor for an internal combustion engine comprising a housing with apassageway therethrough having an inlet and an outlet, a

throttle valve in said passageway, a fuel nozzle, a 1

fuel bowl, a passageway including two branches between the nozzle and the fuel bowl, a metering pin controlling the flow of fuel from the fuel bowl into the two branches, said metering pin having tapered faces adjacent the fuel inlet ends of said branches and operating in unison with the throttle to increase the flow of fuel through the two branches when the throttle is moved toward open position and to decrease the flow of fuel through the two branches when the throttle is moved toward closed position, a positive connection between said metering pin and the valve, and a vacuum controlled valve for shutting off one of said branches when the vacuum i'n'said passageway between the throttle and the outlet.

therethrough, a throttle valve and an air valve. .in said passageway arranged to open and close in unison, a fuel bowl, a fuel jet in said passageway between the throttle and air valves, a first conduit connecting said fuel bowl to said jet, a second conduit connecting said fuel bowl to said first conduit between said jet and the fuel inlet end of said first conduit, a metering pin positively connected to said throttle valve to open in synchronism therewith and simultaneously increase the flow of fuel out of the jet and the flow of air through the main passageway as the throttle opens, said metering pin having tapered faces adjacent the fuel inlet ends of said first and second conduits for controlling and metering the flow of fuel into said conduits, the clearance between the tapered sides of said metering pin and inlet ends of said first and second conduits increasing as the throttle opens, a valve controlling said second conduit, and vacuum controlled means connected into the said passageway on the outlet side of said throttle valve and connected to the valve in the second conduit for shutting off the second conduit whenever the vacuum on the outlet side of the throttle valve is;high and for opening said second conduit whenever the throttle valve is opened sufiiciently to lower the vacuum below a predetermined value whereby the fuel mixture is enriched.

3. A carburetor for an internal combustion engine, said carburetor having a main passageway therethrough with an inlet and an outlet, a throttle valve in said passageway, a fuel bowl, a jet in said passageway on the atmosphere side of said throttle valve, a first passageway connecting said fuel jet to the fuel bowl, a second passageway connecting said first passageway with said fuel bowl, a metering pin positively connected to the throttle valve for opening and closing in synchronism therewith, said metering pin having a shape adjacent the fuel inlet ends of said first and second passageways whereby an increasing clearance between the metering pin and inlet ends of said first and second passageways is produced as the throttle valve opens whereby said metering pin meters the fuel flowing from the fuel bowl into both of the said fuel passageways, a valve for closing said second fuel passageway, a suction controlled device con nected to said fuel valve, and a passageway connecting the suction device with the main passageway of the carburetor on the outlet side of the throttle valve whereby the suction device responds to a decrease in the vacuum in said passageway on the outlet side of'the throttle valve whenever the throttle valve is opened to lower the manifold vacuum below a predetermined value and thereby opens the said fuel valve to permit fuel to flow through the second fuel pas sageway and increase the amount of fuel flowing out of said jet and thereby enrich the fuel mixture.

' MARION MALLORY. 

